I was kinda looking at Krystal across her appearances in how she is characterized and what she's talking about. Some scrapped lore from the leaked Dinosaur Planet build as it was transitioning into SF Adventures, and how they tied the universe together with things like Randorn knowing James etc. Plus Cerinia from the Adventures manual, Animus mentioned in DP64 by Sabre in place of Fox introducing himself to Tricky. Assault and Adventures where Krystal is portrayed as this adventurous, feisty empath, but also Command where she sees the world in a way that isn't just black and white in regards to Andross, as well as having had trouble with her relationship with Fox, due to his own traumas. Albeit massively changed and sanitized from Command. It had a few good ideas, it just needed much more careful writing.

As for Miyu's side of things, her stuff is pure fanon for the most part. Eladard was mentioned to have been a grassy planet in the manual iirc before Venom's forces ruined it with their factories. I imagined that as a bit of an analogue to WWII with children being sent to Britain (Corneria) for safety, that's what happened to Miyu, with Eladard being imagined as more of an old farming colony before Venom arrived.